Process and apparatus for military and naval mining



C. TIETIG PROCESS AND APPARATUS FOR MILITARY AND NAVAL MINING Filed Dec. 17, 1940 Patented Feb. 13, 1945 UNETE SiiS-iii'ihl OFFICE PROCESS AND APPARATUS. FOR IVHLITARY.

AND NAVAL MININGV 7 Claims.

This invention relates to a process and apparatus for military and naval mining. This ap'- plication is a continuation, in part of my copending application Serial No. 361,754, led October 18, 1940.

Among the objects of this invention is to provide a process and apparatus for mining which is absolutely safe until it is armed by the conscious act of an operator, who may be located at a considerable distance from the mine intended to be armed. According t'o my invention, the mined terrain or the mined waters may be used with entire safety by the public with the assurance that even if an unarmed mine is subject to heavy mechanical shock -or electrical disturbances, no major explosion will occur. This is not the case in present practice which involves planting high explosives in terrain and waters which are used by non-hostile persons, who may set off the explosives accidentally.

Another object of my invention is to provide a supplemental process by which an armed mine may be restored to an unarmed condition by remote control.

In the drawing, Figure 1 shows a combined land and water terrain in vertical section, including both land and water mines and if necessary, reservoirs for supplying them.

Figure 2 shows a type of solenoid control valve used on the mines.

In the drawing, III is a building which in practice may be any valuable military objective, say a fort, power plant, mine or the like. I I is a land terrain about the objective IIJ, it being shown as a hill merely for convenience of illustration. lia is a body of water impinging upon the terrain I I, it being shown merely for convenience in illustrating in one view how my invention may be applied to water areas as well as land areas.

Briefly stated, my invention is based upon the fact that an oxidizing salt, such as a chlorate, perchlorate, nitrate, or the like is not by itself explosive, except under extremely unusual circumstances. When such a salt is mixed with easily combustible matter however, themixture is then a high explosive when properly detonated. According to my invention, I provide unarmed land or sea mines which are containers of oxidizing salts alone except for the presence of a detonator. I arm these mines by mixing with the oxidizing salt, a liquid hydrocanbon or its equivalent. This, of course, makes the mines explosive andl explosion can then be brought about 'by sendingT a detonator I2, of the conventional type.

In thezdrawing, I3sis-a1and mine, it'merely being a container preferably of non-corrosive material but permssibly of materiali protected;

against corrosion. Specifically it` may be a steel container coated internally with a non-combustible paint o1" the sodium silicate type, say sodium' silicate plus asbestos powder. In the container I3, there is a lling I4 of an oxidizing salt. It may be in powder form or minutely or coarsely crystalline. The container houses alsothe detonator with. or Without' a booster charge. Cordeau-detonant may also be associated with the primary detcnator. Since sucharrangements are conventional, they are not illustrated in de*- tail. Extending upwardly from the container I3, there is a vent pipe I5 in which there is a check valve I3a suchas that illustrated in Figurey preferably nearftliecontainer wall. TheY purpose. of the pipe and check' valveA will appear hereinafter. The pipe I5 shouldproject into the atmosphere but be protected from becoming clogged with dirt and moisture by a cap I1.

Extending from the container I3v there, is a pipe I8 in which there is a solenoid=or magneticV valve I, which is preferablyV located close to the container I3. Pipe I8l extends to a reservoir 2Q, which is preferablyunder ground and which contains a considerable supply of a volatile liquid hydrocarbon or' mixture' of hydrocarbons', pref erably butane, propanel or natural gasoline. Any liquidv or :liquefied hydrocarbon more volatile than kerosene maybe used. Also-ethyl, methyl o1' isopropyl alcohols or mixtures of them maybe used.y Ethyl ether may also-be used or mixtures of any of the above materials. Butane is a preferred liquid since it has a high volatility coupled with a high caloric value; it is cheapandit generates' its own pressure, thereby in certain cases making pumps unnecessary. With other com-- bustible liquids that are not extremely volatile, pumps may be necessary as will hereinafter appear.

Protected or insulated electric wires'- 251 run preferably as a closable metallic circuitirom the detonators of the various mines toY af control station`2l which may be within the military objective to be protected or it maybe at someother protected location. In the present illustration it' is shown as a switchboard' within the objective IQ. At the station 2I- there can conveniently be an electric generator 22, an engine Zand an air compressor 24. One engine can drive both the generator and the-air compressor since a full load of electricityv andY a full load onthev air com'- pressor will not be'required at the same time.

t can now be explained that the operation of my process comprises mixing the combustible liquid with the oxidizing salt when any such military danger threatens as renders Ait desirable that the terrain II can be blown up at the will of the defenders of the objective I0. To do the mixing, the solenoid valve I9 is opened by remote control from switchboard 2|, thereby allowing combustible liquid to ow either by gravity or its own pressure into container I3, to Wet the oxidizing'salt Ill therein, thereby providing an explosive mixture.

It is now assumed that military necessity requires blowing up the terrain II. This is also accomplished from switchboard 2|y by sending a suitable current through wires 25 thereby ex ploding detonator I 2 and the main charge within the casing I3.

It is now supposed that the mine I3 was prepared by mimng the combustible liquid with the oxidizing salt but that the threatened military necessity did not materialize. Obviously the conventional way of mining is objectionable since it involves a high explosive being left indefinitely under a terrain that may have to be used by non-hostile persons. To obviate this drawback to conventional practice, I have devised the following way of again rendering the mine I3 harmless. To this end I provide a reservoir 26 of dry compressed air which has previously been passed through a moisture trap 21, if desirable. Extending from the reservoir 26, there is a pipe 28 in which there is a solenoid valve 23 preferably close to the reservoir. Through .the pipe 28 a gentle stream of compressed air is directed so as to pass through the container I3 and out of the pipe I5, thereby volatilizing'the combustible liquid or expelling it as a liquid. To assist the latter operation, the pipe I5 may be directed downwardly instead of upwardly, a downwardly directed pipe being shown as Itla. Also, to assist expulsion of the liquid as a liquid instead of a vapor, the pipe 28 may enter the top of container I3 instead of the bottom. To this end connection 28a is provided so that a part of the hydrocarbon pipe I8 may be used. Check valves I3a are used in the case of very volatile liquids like butane, and are electro-magnetically controlled so that the container when full of o-xidizing salt and volatile liquid may be closed off to prevent the butane from spontaneously evaporating. It is therefore possible to hold the mine in an armed condition as long as is necessary and after the necessity has passed, to then unarm the mine by remote control so that the entire system is not dangerous to the public or to the operator.

The remainder of the invention relates to the method of charging and arming water mines. In the drawing, two such 30 and 3| are shown under the surface of a body of water IIa. Each of these mines has a casing I3 and an electric detonator I2 with appropriate wires25 extending to switchboard 2I. Combustible liquid is supplied through a pipe I8 containing a magnetic valve I 9, the portion of the pipe I8 where it extends through the water being flexible and indicated as l8a. The Water mines may be arranged in series as shown, or in parallel by means of connecting flexible tubing which is lined preferably with oil proof rubber known as neoprene or ThiokoL The flexibility of the tubing, which should have considerable slack, enables the mines to move without losing their essential connections.

Each water mine is also provided with a remotely controlled check valve I5 in a pipe I5 just as the land mines have. The pipe I5 need not however, project beyond the waters surface. The water mines are also provided with a remote-control dump valve I6, of the same type as used in pipe I5 and in case of the land mines, also in pipe I5a.

If it is desired to iill the mines with a charge to their full capacity, air and vapors are avoided by opening the valves I6 in the pipes I5 when the back pressure in lling pipes I 8 balances the forward pressure. This operation is suitable for either land or sea mines when butane is used. The pressure on the filling liquid is kept in all cases higher than the head ofrwater over the water mines so that no wetting of the oxidizing salt will occur. As soon as the mines are full, as can be told by metering the liquid passingr through the pipes I8 and comparing it with the known volume of the mines, valves I6 are closed. In general, perfect stoichiometrical ratios between the oxidizing salt and the combustible liquid should be aimed at, but if a perfect ratio is not attained, still the charge will detonate, a1- though not so powerfully, My invention also includes the use of liquids less volatile than kerosene for uses in which it is not desired to unarm the mine after it is armed.

As oxidizing agent, I prefer to use ammonium perchlorate, however I may use an alkali-metal chlorate or ammonium nitrate or sodium nitrate with ammonium nitrate. In fact I may use any compatible combination of oxidizing salts. tures of ammonium nitrate and chlorates cannot be used.

In the foregoing description, it should be understood that a motor operated valve can be substituted for a solenoid operated valve and that both types should be enclosed in metal gauze so as to be explosion proof so as not to ignite hydrocarbon vapors.

Where it is desired to use combustible liquids which do not generate their own pressure and to feed such liquids into the mine from reservoirs which do not have a hydrostatic head, pumps may be employed. They may also be remotely controlled.

While for the purposes of convenience, an electric method of control has been shown, it lies within the purview of the invention to substitute a pneumatic or hydraulic control.

I make no claim here to the valve illustrated in Figure 2 except as part of the combination of mining apparatus. In this figure, 4I is the body of the valve, 3l the hinged check ilap, 32 a solenoid, 33 a stem on the solenoid, 3i a stufiing box. .35 a hinge between the ap 32 and stem 33, and 36 is a support for the solenoid 32.

A modified form of mine is shown in Figure l. It is that water mine 40 which is furthest to the left on the drawing. In this form, the two com ponents of the main charge are kept in a single containerl3 which is divided by a leak proof wall 31. 38 and 39 within the mine of which 38 holds the oxidizing salt and 39 holds the combustible liquid. While I have shown the mine divided vertically by the wall, it may be divided horizontally or at any other angle.

In the wall 31 there is a valve I6 of the type shown in Figure 2, including appropriate wiring.

. A detonator I2 is provided in the compartment 38. 'Valve I6 is located preferably in the lower part of wall 31 so that the liquid can Ilow by Mix- This wall creates two compartments,l

gravity into the lcompartment 38. It is not necessary for all of the liquid to flow on to the salt in all cases since the compartments 38 and 39 maybe of different sizes yto suit the nature of the liqiud and salt used. In the dual compartment style of mine just described, a vent for vapor is not necessary since the liquid compartment can be iilled in a factory under conditions allowing for escape of air. Ii desired, air can be exhausted from the salt compartment so that when the valve Iii is opened, the liquid will be sucked into contact with the salt to a substantial extent. Such a type of mine is advantageous on account of the speed with which it can be armed. A dual compartment mine of this nature can be used also for land work as well as for marine. In both kinds of use it is safe until armed.

It is to be understood that yWherever necessary to protect the solenoid valves from sea Water, hydrocarbons, corrosion from salts or other attack, they may befenclosed in separate small compartments. For leak-proofing compartments, I prefer welded construction. Where it is necessary that wires should pass through hydrocarbons, they may be insulated with Thiokol o1; Neoprene.

Generally, the crystals of oxidizing salt will have enough voids between them to accommodate a stoichiometric amount of combustible liquid. Little if any additional space to accommodate liquid is therefore necessary.

It is to be understood that the passage of the solid salt into the pipes may be prevented by placing ne metal gauze over the entrances to the pipes.

While I have shown a specific type of valve, it is to be understood that other types of valve may be used so long as they can be controlled from a long distance. For example, a motor operated` needle valve may be substituted for the check valve. In Figure l of the `drawing, a common return for all of the electrical circuits is indicated by R. It is to be understood of course, that each individual circuit may have its own return but generally this will not be found necessary.

It should be noted that when quick expulsion of the combustible liquid from the mine is desired, the outlet or dump I5a should be located at a point lower than the air and liquid inlet pipe 18a. In order to prevent water from flowing into the mine during the process of de-arming, air pressure should be turned into the mine before the outlet or dump valve is opened and the condition should be such that suicient air pressure should be 4kept on the mine during the process of de-arming to prevent water from owing back. In order to then relieve pressure from the mine so that an additional charge of combustible liquid may be injected into it at some future time, the pipe I8 or |8a. should be bled to the atmosphere to get rid of the pressure within it.

Mines such as that shown at 40 can be dearmed by nrst opening the valve in the partition and then opening the dump valve I6, Compressed air will then now through the partition valve and out of the dump valve, volatilizing the liquid or expellin-g it as liquid, The valve should then be closed.

In order to eliminate leakage of very light hydrocarbons through the valves, it is recommended that motor operated needle valves be used, or if check valves of the type illustrated in Figure 2' be' used, that they should be provided with Neoprenemor Thiokol'valve seats.

I claim as my invention: 1. The process of unarming a mine of the type inwhich the explosive charge is a mixture of a solid oxidizing salt and a volatile combustible vliquid which comprises passing air through said charge until'said liquid is completely evaporated.

2. A process of unarming a mine of the type in which the explosive charge comprises a mixture of a solid oxidizing salt and a volatile combustible uid conned within a closed container, which comprises passing a gas through said charge until the uid is expelled from the container, said gas being non-explosively reactive with. respect to the oxidizing salt.

3. A mine adapted for military or naval use comprising a closed container for an explosive charge, a reservoir for a volatile fluid comprising one of the essential components of the explosive charge, an inlet conduit extending between said reservoir and container, a valve for opening and closing passage through said inlet conduit, control means for actuating said valve, a source of air under pressure, an air conduit extending between said air source and container, a valve for opening and closing passage through said air conduit, control means for actuating said air-conduit valve, an escape vent in said container for releasing gases therefrom, a detonator for the explosive charge, and means for ring said detonator, said valve-control means and said-detonator-firing means being remotely located from said container.

4. A mine adapted for military or naval use comprising a closed container for an explosive charge, a reservoir for a volatile fluid comprising one of the essential components of the explosive charge, an inlet conduit extending be- 40 tween said reservoir and container, a solenoid Valve for opening and closing passage through said inlet conduit, a source of air under pressure, an air conduit extending between said air source and container, a solenoid valve for opening and' closing passage through said air conduit, control circuits for actuating said valves, an escape vent in said container for releasing gases therefrom, a detonator for the explosive charge, and means for iiring said detonator, both said Valve-control circuits and said detonator-ring means being remotely located from said container.

5. A mine adapted for military or naval use comprising a closed container for an explosive charge, said charge including as one of its essential components an oxidizing salt adapted to be preliminarily provided within the container, a reservoir for a volatile combustible iiuid comprising another essential component of the explosive charge, an inlet conduit extending between said reservoir and container, a solenoid valve for opening and closing passage through said inlet conduit, a source di" air under pressure, an air conduit extending between said air source and container, a solenoid valve for opening and closing passage through said air conduit, an escape vent in said container for releasing gases therefrom, a solenoid valve for opening and closing said escape vent, a detonator for the explosive charge, electrical circuits for actuating said solenoid valves and for firing said detonator, and control means for closing said electrical circuits remotely locatedfrom said container.

6. A submersible mine adapted for, naval use comprising a closed buoyant container for an conduit, an escape vent in said container for re.. leasing gases therefrom, a solenoid valve for opening and closing said vent, a detonator for the explosive charge, and remotely controlled electrical circuits for actuating said solenoid valves and for firing said detonator.

'7. A containerfor an explosive charge for use in military or naval mining, said container comprising a fluid inlet, an air inlet, an escape vent and solenoid-operated valves for opening and closing said inlet, outlet and escape vent.

CHESTER TIETIG. 

